Prestone® 50/50 Prediluted antifreeze/coolant is the convenient way to top off your car?s cooling system with the superior protection of Prestone® Antifreeze. Fortified with the new patented Cor-Guard? improved extended life technology, Prestone prevents corrosion and helps keep your cooling system running more efficiently. Keep your entire cooling system, including your radiator and water pump, free from the damaging effects of worn-out antifreeze.